1. Field of the Invention
This invention relates to flame retardant and smolder resistant compositions for backcoating textile or interliner materials. More particularly, this invention relates to rendering textiles, generally upholstery textiles or upholstery interliner materials, flame retardant and smolder resistant.
2. Relevant Art
By textile is meant, hereinafter, a fabric, filament, staple, or yarn, or products made therefrom, which may be woven or non-woven.
Rendering textiles flame retardant or smolder resistant is of importance for the improvement of the safety characteristics of apparel, bedding, protective clothing, tents, cloth, carpets, home furnishings, aircraft and automobile interior fabrics, and industrial fabrics which may be woven, knitted, tufted and non-woven.
Fire hazards associated with upholstered furniture are well known, and little has been done in changing the smoldering characteristics by imparting smolder resistance to such fabrics.
Presently upholstery fabric is backcoated for dimensional stability and to improve wearability utilizing various polymeric materials. Some chlorine-containing polymers have been found to be smolder retardants when used as backcoatings, Donaldson, Mard and Harper, Imparting Smolder Resistance to Cotton Upholstery Fabric, Textile Research Journal 49, 185-190 (1979). The use of these polymers in backcoating, is, however, not satisfactory due to high levels of add-ons necessary to achieve the smoldering resistance for adequate protection. Furthermore, these high levels result in objectionable aesthetics (hand) to the treated material.
It has also been disclosed to utilize boric acid, by dusting or vapor phase methyl borate hydrolysis techniques, to impart smolder resistance at relatively low add-ons. Commercial use of this process has, however, been hindered by the problem of permanence, availability of application equipment and cost. In an attempt to overcome the cost and equipment factors of utilizing boric acid, a smolder resistant finish based on borax has been suggested, see Donaldson and Harper, A Borax-Nitrogen-Phosphorous System For Imparting Smolder Resistance to Upholstery Fabrics, Journal of Consumer Products Flammability, Vol. 7, No 1, 40-47 (March 1980). This method provides for dissolving the less costly borax in phosphoric acid and applying the mexture in combination with methylolated melamine via a pad, dry-cure procedure.
It has further been disclosed to utilize sulfur to impart smolder resistance to upholstery fabrics. This, however, has caused odor problems.
U.S. Pat. No. 3,746,572 to Weil et al. discloses a process for flame retarding textiles comprising applying to the textile an aqueous solution consisting of a polyol phosphonate, dimethylol dihydroxyethylene urea and a curing catalyst and curing the phosphonate and urea on the textile and thereby rendering the textile flame retardant. The method of application is by padding and thereby impregnating the fabric with the flame retardant material. Although this process provides adequate flame retardant properties, it cannot be used satisfactorily to provide smolder retardance particularly in upholstery fabric. A wet impregnation of upholstery fabric would be injurious to fabric hand as well as costly in the chemicals utilized, and the energy expended for drying. In addition, applications of this type on velvets would negate the asthetic appeal of this soft pile fabric.